Dietary effect of different fermented feed sources on growth performance of early juvenile sea cucumber Holothuria scabra

Abstract

The development of effective, economically viable and locally sourced diets for high-value early juvenile sea cucumber, Holothuria scabra, is important to ensure efficient juvenile production for sustainable farming and ranching. The current study applies seven fermented algal/plant diet formulations (C (control), diet seagrass Enhalus acoroides; DH, diet macroalgae Halimeda discoidea, DU, diet macroalgae Ulva lactuca, DP, diet macroalgae Padina australis, DS, diet macroalgae Sargassum polycystum, DA, diet green pond algae; DM, diet pond moss) in controlled feeding experiments for post-metamorphic juvenile H. scabra. The highest overall mean ( ± SE) individual growth rate of 0.09 ± 0.023 g d−1 was recorded for the diet green pond algae (DA), however, this diet also exhibited the lowest individual survival rate across all treatments. Combined acceptable growth rates of 0.03 ± 0.001 and 0.03 ± 0.002 g d−1, and much higher survival rates of 80.63 ± 4.38 and 80.63 ± 2.77%, respectively were recorded for diets E. acoroides (C), and Padina sp. (DP). The reasons for significant variations and survival rates are not known, however, these results indicate that the diets with acceptable survival rates may be better suited for very early juvenile sea cucumbers. Those diets exhibiting highest overall individual growth rate in the long-term may be better applied to juveniles of larger sizes later in the nursery production process. Overall results indicate good acceptance of most macroalgae fermented diets by juvenile H. scabra. Results also indicate that piloting diets at larger scales and at a variety of sizes and ages will allow determination of optimal feeding throughout the nursery production process.